Geoskill: RS Index Calc

Calculate 10 spectral indices from GeoTIFF imagery using pure Python without external dependencies, supporting batch, custom formulas, and auto band detection.

Remote Sensing Index Calculator

Calculate spectral indices from GeoTIFF imagery using pure Python. No external dependencies required.

Features

• 10 Supported Indices: NDVI, NDBI, NDWI, EVI, SAVI, MNDWI, AWEI, NBR, BSI, UI
• Pure Python: No rasterio, GDAL, numpy, or scipy required
• Auto Band Detection: Automatically detects band mapping from GeoTIFF metadata
• Custom Formulas: Support for arbitrary band math expressions
• Batch Mode: Calculate all indices at once
• Statistics: Automatic min/max/mean/std computation

Installation

bash

pip install -r requirements.txt
# No external dependencies - uses only Python standard library

Usage

Single Index

bash

python rs-index-calc.py input.tif NDVI
python rs-index-calc.py input.tif NDVI --output ndvi_result.tif

All Indices (Batch Mode)

bash

python rs-index-calc.py input.tif --batch

Custom Formula

bash

python rs-index-calc.py input.tif custom --formula "(B4-B3)/(B4+B3)"

Manual Band Order

bash

python rs-index-calc.py input.tif NDVI --bands red nir green blue swir1 swir2

Supported Indices

Index	Formula	Bands
NDVI	(NIR - Red) / (NIR + Red)	NIR, Red
NDBI	(SWIR - NIR) / (SWIR + NIR)	SWIR, NIR
NDWI	(Green - NIR) / (Green + NIR)	Green, NIR
EVI	2.5 * (NIR - Red) / (NIR + 6Red - 7.5Blue + 1)	NIR, Red, Blue
SAVI	(NIR - Red) / (NIR + Red + 0.5) * 1.5	NIR, Red
MNDWI	(Green - SWIR) / (Green + SWIR)	Green, SWIR
AWEI	4*(Green-SWIR) - (0.25NIR + 2.75SWIR)	Green, SWIR, NIR
NBR	(NIR - SWIR2) / (NIR + SWIR2)	NIR, SWIR2
BSI	((SWIR+Red)-(NIR+Blue)) / ((SWIR+Red)+(NIR+Blue))	SWIR, Red, NIR, Blue
UI	(SWIR2 - NIR) / (SWIR2 + NIR)	SWIR2, NIR

Output

• Single-band GeoTIFF with calculated index values
• Statistics printed to stdout (min, max, mean, std, pixel count)

Testing

bash

pytest

License

MIT-0 (No Attribution)

---

中文说明

从 GeoTIFF 影像计算光谱指数，纯 Python 实现，无需任何外部依赖。

支持的指数（10 种）

指数	公式	波段
NDVI	(NIR - Red) / (NIR + Red)	NIR, Red
NDBI	(SWIR - NIR) / (SWIR + NIR)	SWIR, NIR
NDWI	(Green - NIR) / (Green + NIR)	Green, NIR
EVI	2.5 * (NIR - Red) / (NIR + 6Red - 7.5Blue + 1)	NIR, Red, Blue
SAVI	(NIR - Red) / (NIR + Red + 0.5) * 1.5	NIR, Red
MNDWI	(Green - SWIR) / (Green + SWIR)	Green, SWIR
AWEI	4*(Green-SWIR) - (0.25NIR + 2.75SWIR)	Green, SWIR, NIR
NBR	(NIR - SWIR2) / (NIR + SWIR2)	NIR, SWIR2
BSI	((SWIR+Red)-(NIR+Blue)) / ((SWIR+Red)+(NIR+Blue))	SWIR, Red, NIR, Blue
UI	(SWIR2 - NIR) / (SWIR2 + NIR)	SWIR2, NIR

使用方法

bash

# 计算单个指数
python rs-index-calc.py input.tif NDVI
python rs-index-calc.py input.tif NDVI --output ndvi_result.tif

# 批量计算所有指数
python rs-index-calc.py input.tif --batch

# 自定义公式
python rs-index-calc.py input.tif custom --formula "(B4-B3)/(B4+B3)"

# 手动指定波段顺序
python rs-index-calc.py input.tif NDVI --bands red nir green blue swir1 swir2

输出

• 单波段 GeoTIFF，值为指数计算结果
• 自动输出统计信息（最小值、最大值、均值、标准差、像元数）